Anchor and anchor-free methods are known in order to fasten cleaning elements, such as bristle tufts, in a bristle carrier or the brush head of a toothbrush. The anchor-free or hot-tufting methods fasten the cleaning elements in the brush head by means of a forming technique. Usually, the bristle tufts are melted at their ends to form thickenings in order to increase the pull-out resistance of the tufts. These thickenings can be over-molded with a plastic material to form a bristle carrier or a brush head, or the thickenings can be cast in a bristle carrier or a brush head mechanically by other forming techniques.
Theoretically these methods allow to generate bristle fields with different properties in different areas. In order to optimize the cleaning efficiency of toothbrushes, it may be helpful to provide different cleaning elements in different sections of the bristle field or to support cleaning elements or bristle tufts in a different manner, for example, to support a portion thereof rigidly in a section of hard plastic and another portion thereof flexibly in a section of soft plastic. To achieve these results it may be beneficial to melt the ends of differently composed groups of cleaning elements, for example, consisting of different bristle material, to different degrees, in order to achieve an optimum anchoring. However, this is difficult using hot-tufting methods which melt the ends of the tufts after the tufts have been configured into the desired bristle field, because the usually required application of heat to a bristle tuft always also affects adjacent tuft ends. This becomes even more difficult when not only bristle tufts but also differently designed cleaning elements, such as strips of soft plastic, are to be used and to be combined, for example, with bristle tufts.
Accordingly, there is a need for a toothbrush head and manufacturing method thereof, which allows for design flexibility, material flexibility, and support flexibility.